Compound action potentials (CAP) and action potential-summating potential complex (AP-SP) evoked by click and tone burst respectively were recorded from the round window in guinea pigs. Correlations between the positi...Compound action potentials (CAP) and action potential-summating potential complex (AP-SP) evoked by click and tone burst respectively were recorded from the round window in guinea pigs. Correlations between the positive and negative summating potentials (SP+ and SP-) were examined before and after impulse sound exposure. The results show that the SP- is related to the threshold shift of CAP. In comparison to normal condition, it appears with a high incidence when the auditory threshold shift reaches 30 dB or more. SP-increases in amplitude when SP+ decreases. The smaller the amplitude of SP+, the larger that of SP-. This suggests that in normal hearing condition SP- may be suppressed by SP+. Such suppression may be released if OHCs are injured. The dominant SP- as a sign of recruitment may be due to the change in the nonlinear character of IHC following OHC damage.展开更多
文摘Compound action potentials (CAP) and action potential-summating potential complex (AP-SP) evoked by click and tone burst respectively were recorded from the round window in guinea pigs. Correlations between the positive and negative summating potentials (SP+ and SP-) were examined before and after impulse sound exposure. The results show that the SP- is related to the threshold shift of CAP. In comparison to normal condition, it appears with a high incidence when the auditory threshold shift reaches 30 dB or more. SP-increases in amplitude when SP+ decreases. The smaller the amplitude of SP+, the larger that of SP-. This suggests that in normal hearing condition SP- may be suppressed by SP+. Such suppression may be released if OHCs are injured. The dominant SP- as a sign of recruitment may be due to the change in the nonlinear character of IHC following OHC damage.
